html, body {
    margin: 0;       /* remove the default margin          */
    height: 100%;    /* make the html,body fill the page   */
  }
  canvas {
    display: block;  /* make the canvas act like a block   */
    text-align: center;
  }
  #display-values {
    position: absolute;
    top: 0;
    left: 0;
    margin: 0;
    padding: 0.5em;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
  }